Ap chem lab
Emission Spectroscopy Lab
Introduction: According to the Bohr atomic model, electrons orbit the nucleus in fixed paths with specific energies. Each path is therefore often referred to as an “energy level”. Electrons possessing the lowest energy are found in the levels closest to the nucleus. Electrons of higher energy are located in progressively more distant energy levels.
If an electron absorbs sufficient energy to bridge the “gap” between energy levels, the electron may jump to a higher level and become “excited”. Since this change results in a vacant lower orbital, the configuration is unstable. The excited electron releases its newly acquired energy and falls back to its initial or “ground state”. Sometimes the excited electrons acquire sufficient energy to make several energy level transitions. When these electrons return to their ground state, several distinct energy emissions occur. Electrons may become excited when a sample of matter is heated or subjected to an electrical current. The energy that electrons emit when returning to the ground state is electromagnetic radiation, or EMR. Sometimes the EMR can be seen as visible light.
In 1900, Max Planck studied visible emissions from hot glowing solids. He proposed that light was emitted in packets of energy called quanta and that the energy of each packet was proportional to the frequency of the light wave. According to Einstein and Planck, the energy of the packet could be expressed as the product of the frequency () of emitted light and Planck’s constant (h). E=h•
When white light passes through a prism its component wavelengths are bent at different angles. This produces a rainbow of colors known as a continuous spectrum. If, however, the light emitted from hot gases or energized ions is viewed in a similar manner, isolated bands of color are observed. Each band represents a specific energy level change of electrons in the atoms. Since the atoms of each element contain unique
Introduction: According to the Bohr atomic model, electrons orbit the nucleus in fixed paths with specific energies. Each path is therefore often referred to as an “energy level”. Electrons possessing the lowest energy are found in the levels closest to the nucleus. Electrons of higher energy are located in progressively more distant energy levels.
If an electron absorbs sufficient energy to bridge the “gap” between energy levels, the electron may jump to a higher level and become “excited”. Since this change results in a vacant lower orbital, the configuration is unstable. The excited electron releases its newly acquired energy and falls back to its initial or “ground state”. Sometimes the excited electrons acquire sufficient energy to make several energy level transitions. When these electrons return to their ground state, several distinct energy emissions occur. Electrons may become excited when a sample of matter is heated or subjected to an electrical current. The energy that electrons emit when returning to the ground state is electromagnetic radiation, or EMR. Sometimes the EMR can be seen as visible light.
In 1900, Max Planck studied visible emissions from hot glowing solids. He proposed that light was emitted in packets of energy called quanta and that the energy of each packet was proportional to the frequency of the light wave. According to Einstein and Planck, the energy of the packet could be expressed as the product of the frequency () of emitted light and Planck’s constant (h). E=h•
When white light passes through a prism its component wavelengths are bent at different angles. This produces a rainbow of colors known as a continuous spectrum. If, however, the light emitted from hot gases or energized ions is viewed in a similar manner, isolated bands of color are observed. Each band represents a specific energy level change of electrons in the atoms. Since the atoms of each element contain unique